People suffering from cardiac arrest are more likely to survive if it happens in public, a Wellington-wide study has found.

It doesn't seem to matter whether victims collapse at home in a wealthy suburb or a poor one - the number of bystanders who know cardiopulmonary resuscitation (CPR) is the same, and the ambulance response times are just as swift, which is not always the case in other countries cited in the research, such as South Korea and the United States.

"If you have a cardiac arrest at home, it doesn't matter where you are - whether Cannons Creek or Kelburn - the outcomes are the same," said Peter Larsen, co-author of the joint University of Otago and Wellington Free Ambulance study.

The research looked at data collected between 2007 and 2010 on 413 out-of-hospital cardiac arrest patients aged 16 and over, who were given resuscitation.

It found bystander CPR rates were much higher in public cardiac arrests, at 73.3 per cent, than when attacks happened at a house, at 44.3 per cent. Nearly 80 per cent of the cardiac arrests happened at home and the rest in public.

Survival rates for cardiac arrests in public were better because they were witnessed, paramedics arrived faster, and victims were more likely to receive CPR, Larsen said.

The research pointed to an "egalitarian, equitable" health system in the Greater Wellington region, which has a population of 473,000 and is serviced exclusively by Wellington Free Ambulance.

Wellingtonians were also more likely to know CPR because the procedure was taught across the board in schools and workplaces of all socio-economic groups.

The research also showed Kiwis were good at rolling up their sleeves and mucking in.

"This does suggest New Zealanders are willing to get involved and do something to help to a greater extent than other countries where people might be fearful of getting involved," Larsen said.

Wellington Free Ambulance emergency medical consultant and study co-author Andy Swain said the results were encouraging, as the research showed no-one in the region was being deprived of prompt emergency treatment and there was no socio-economic bias.

When cardiac arrest happened in a "public arena" - such as a stadium, railway station or on the street - survival rates were better because rapid CPR made heart rhythms "more amenable to an electric shock", Swain said.

Cardiac arrests after drowning, trauma or attempted suicide were excluded from the study, as were those in the presence of paramedics or at medically equipped facilities, such as nursing homes or doctors' surgeries.

Chad Russell says CPR performed by his wife saved him from severe brain damage or death.

The 37-year-old Lower Hutt information technology projects manager was about to sit down for dinner when he blacked out, hit his head on the breakfast bar and smashed his glasses.

His wife, Sarah, thought he was "playing silly buggers" but soon realised it was real as the couple's then 18-month-old daughter, Luka, was "screaming her lungs out".

The drama ramped up as dinner burned in the frying pan and set off a smoke alarm.

Mrs Russell already knew CPR, which she performed with guidance from a 111 operator while waiting for paramedics and firefighters, who both arrived within 10 minutes.

Paramedics tried to shock Mr Russell four or five times to get a solid heartbeat, then decided to take him to nearby Hutt Hospital.

He had an implantable cardioverter-defibrillator fitted on his 36th birthday and says it took about a year to get over the psychological trauma of the near-death experience.

He has donated more than $2000 towards an automated external defibrillator (AED) for Lower Hutt's Pak 'n Save supermarket.

There are 30 community AEDs in the region and Wellington Free Ambulance aims to install 30 more next month. A further 200 are owned by private businesses.

The University of Otago and Wellington Free Ambulance research was fantastic, Mr Russell said.

"The more people are aware of cardiac arrest and the location of AEDs, the more they can help people."

CARDIAC ARREST: WHAT TO DO

Call 111 if you suspect someone has had a cardiac arrest. The call-taker will help establish if you're dealing with cardiac arrest or something more minor, such as fainting.

Once cardiac arrest has been identified, an ambulance will be activated and the call-taker will talk the rescuer through giving CPR. Phone assistance will still be provided even if you already know CPR.

After six minutes of chest compressions, you will be asked to perform a two-breath mouth-to-mouth resuscitation, then continue with chest compressions until paramedics arrive.

HEART ATTACK OR CARDIAC ARREST?

Heart attack: When coronary arteries - the blood vessels that supply the heart - become blocked, causing lack of blood to the heart. Chest pains are the most common symptom. It is critical that the blockage is fixed within hours, otherwise heart muscle will die. About 25,000 people have heart attacks every year.

Cardiac arrest: When the heart stops pumping blood around the body. It causes loss of consciousness within seconds, and is fatal if blood flow is not restored to the patient's heart and brain within minutes. The most common cause is a heart attack, but not all heart attacks cause cardiac arrest - only about 10 per cent result in the heart stopping. Other causes include diseases such as enlargement of the heart and pulmonary embolism. About 2000 people suffer cardiac arrest every year in New Zealand.